Ultrasound promoted environmentally benign, highly efficient, and chemoselective N-tert-butyloxycarbonylation of amines by reusable sulfated polyborate

The sulfated polyborate catalyzed an efficient and chemoselective N-tert-butyloxycarbonylation of amines under ultrasonic irradiation is developed. A broad substrate scope has been demonstrated for N-Boc protection various primary/secondary amines. It allows converting several aliphatic/aryl/heteroaryl amines, amino alcohol, aminoester, chiral to their N-Boc-protected derivatives solvent-free conditions with excellent yields. protocol advantages such as easy catalyst, product isolation, short reaction time, yields, outstanding chemoselectivity, catalyst recyclability, among others. This makes the process practicable, economical, environmentally benign.